Can you tell if the steelhead you just caught is a wild fish or of hatchery origin?

It’s a question I get asked all the time…”How can I tell the difference?”

It’s important information because in many places, it’s legal to only to keep hatchery steelhead. In other words, wild fish must be released.

And, honestly, even in the handful of places where a wild steelhead can be retained, they should be released voluntarily anyway. There simply aren’t that many of them left and they are of much greater value on the spawning gravels than on a grill.

Hatchery Steelhead

Hatchery steelhead will be missing their adipose fin, which is the small fleshy one on the back between the dorsal fin and tail.

Prior to release from the hatchery, the fin is removed from juvenile steelhead (via scissors or automated machine).

Since it never grows back, the lack of the adipose fin on an adult fish makes it easy to identify as of hatchery origin…and, therefore, in many rivers, legal to keep (check the regs before you go to make sure!).

You’ll sometimes encounter a fish that’s a “tweener” — one that has a partial adipose fin. While this can occur in the wild (rare), it is more often the byproduct of a “miss-clip” by the person doing the fin removal.

Where done by hand, you can imagine that there are going to be some imperfect cuts when people are trying to get through tens of thousands of baby Steelhead.

One other clue to look for, however, is sign of an eroded dorsal fin. When jammed together in fish hatcheries, baby steelies often rub against each other and the concrete walls, resulting in worn down fins.

And here’s another example…

These two examples are pretty obviously hatchery steelhead but what about this one below….?

The dorsal in the above fish is pretty intact and there’s more than a just nub of an adipose but I’m still sure this one is a hatchery steelie (we let it go anyway). If you have any doubt whatsoever my advice is to let the fish go!

Now, before you get any ideas about bringing a pair of scissors with ya to the river, note that most regulations read something along these lines: The adipose fin must be missing and the wound must be healed…

Unfortunately, there are some pea-brained “anglers” out there who fish in the spring when the smolts are out-migrating and clip the fins off wild ones so they can be kept upon return as adults. Lame lame lame!

Wild Steelhead

Of course, wild steelhead will be proudly sporting a fully-intact adipose fin and should always be released carefully with minimal handling.

When you see that your fish has an adipose, it’s best to refrain from netting it, unless you have one of those fish-friendly knotless nets. Also try to avoid dragging it up in the rocks.

Whenever possible, I’ll gently beach them in the shallows, where I can quickly unhook it and snap a photo. Be advised that in places like Washington State, it is illegal to lift a wild steelhead out of the water for a photo.

That doesn’t mean, however, you can’t get a pic. Simply kneel down in the water with the fish. That way, if it squirms and you loose your grip, you’re not dropping it from altitude down onto the rocks.

Of course, if you catch a hatchery fish and it’s legal to keep it, by all means take good care of it and enjoy fresh fish on the grill. Many hatchery managers encourage you to keep clipped fish so don’t feel guilty if you want to take one for dinner…

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